set correct R/C values for SG nodes

soheilshahrouz · soheilshahrouz · commit 219dd038709e · 2025-10-27T15:51:38.000-04:00
diff --git a/libs/librrgraph/src/base/rr_rc_data.cpp b/libs/librrgraph/src/base/rr_rc_data.cpp
@@ -4,24 +4,24 @@ t_rr_rc_data::t_rr_rc_data(float Rval, float Cval) noexcept
     : R(Rval)
     , C(Cval) {}
 
-short find_create_rr_rc_data(const float R, const float C, std::vector<t_rr_rc_data>& rr_rc_data) {
+NodeRCIndex find_create_rr_rc_data(const float R, const float C, std::vector<t_rr_rc_data>& rr_rc_data) {
 
     auto match = [&](const t_rr_rc_data& val) {
         return val.R == R
                && val.C == C;
     };
 
-    //Just a linear search for now
+    // Just a linear search for now
     auto itr = std::find_if(rr_rc_data.begin(),
                             rr_rc_data.end(),
                             match);
 
     if (itr == rr_rc_data.end()) {
-        //Not found -> create it
+        // Not found -> create it
         rr_rc_data.emplace_back(R, C);
 
-        itr = --rr_rc_data.end(); //Iterator to inserted value
+        itr = --rr_rc_data.end(); // Iterator to inserted value
     }
 
-    return std::distance(rr_rc_data.begin(), itr);
+    return NodeRCIndex(std::distance(rr_rc_data.begin(), itr));
 }
diff --git a/libs/librrgraph/src/base/rr_rc_data.h b/libs/librrgraph/src/base/rr_rc_data.h
@@ -10,4 +10,4 @@
  *
  * The returned indicies index into DeviceContext.rr_rc_data.
  */
-short find_create_rr_rc_data(const float R, const float C, std::vector<t_rr_rc_data>& rr_rc_data);
+NodeRCIndex find_create_rr_rc_data(const float R, const float C, std::vector<t_rr_rc_data>& rr_rc_data);
diff --git a/libs/librrgraph/src/io/rr_graph_uxsdcxx_serializer.h b/libs/librrgraph/src/io/rr_graph_uxsdcxx_serializer.h
@@ -806,7 +806,8 @@ class RrGraphSerializer final : public uxsd::RrGraphBase<RrGraphContextTypes> {
     inline int init_node_timing(int& inode, float C, float R) final {
         auto node = (*rr_nodes_)[inode];
         RRNodeId node_id = node.id();
-        rr_graph_builder_->set_node_rc_index(node_id, NodeRCIndex(find_create_rr_rc_data(R, C, *rr_rc_data_)));
+        const NodeRCIndex rc_index = find_create_rr_rc_data(R, C, *rr_rc_data_);
+        rr_graph_builder_->set_node_rc_index(node_id, rc_index);
         return inode;
     }
     inline void finish_node_timing(int& /*inode*/) final {}
@@ -934,7 +935,7 @@ class RrGraphSerializer final : public uxsd::RrGraphBase<RrGraphContextTypes> {
                     type);
         }
 
-        rr_graph_builder_->set_node_rc_index(node_id, NodeRCIndex(find_create_rr_rc_data(0, 0, *rr_rc_data_)));
+        rr_graph_builder_->set_node_rc_index(node_id, find_create_rr_rc_data(0, 0, *rr_rc_data_));
 
         return id;
     }
diff --git a/vpr/src/route/rr_graph_generation/build_scatter_gathers.cpp b/vpr/src/route/rr_graph_generation/build_scatter_gathers.cpp
@@ -306,6 +306,8 @@ std::vector<t_bottleneck_link> alloc_and_load_scatter_gather_connections(const s
 
                     bottleneck_link.chan_type = chan_type;
                     bottleneck_link.parallel_segment_index = std::distance(segment_inf.begin(), seg_it);
+                    bottleneck_link.R_metal = seg_it->Rmetal;
+                    bottleneck_link.C_metal = seg_it->Cmetal;
 
                     if (is_3d_link) {
                         if (sg_link.z_offset < 0 && wire_segment.arch_wire_switch_dec != ARCH_FPGA_UNDEFINED_VAL) {
diff --git a/vpr/src/route/rr_graph_generation/build_scatter_gathers.h b/vpr/src/route/rr_graph_generation/build_scatter_gathers.h
@@ -33,6 +33,8 @@ struct t_bottleneck_link {
     t_physical_tile_loc scatter_loc; ///< Destination switchblock location.
     int arch_wire_switch;            ///< The switch (mux) used to drive the bottleneck wire.
     int parallel_segment_index;
+    float R_metal;
+    float C_metal;
     e_rr_type chan_type;
     std::vector<t_sg_candidate> gather_fanin_connections;   ///< Wires driving the bottleneck link at  `gather_loc`
     std::vector<t_sg_candidate> scatter_fanout_connections; ///< Wires driven by the bottleneck link at `scatter_loc`
diff --git a/vpr/src/route/rr_graph_generation/clock_connection_builders.cpp b/vpr/src/route/rr_graph_generation/clock_connection_builders.cpp
@@ -114,9 +114,8 @@ RRNodeId RoutingToClockConnection::create_virtual_clock_network_sink_node(int la
     rr_graph_builder.set_node_capacity(node_index, 1);
     rr_graph_builder.set_node_cost_index(node_index, RRIndexedDataId(SINK_COST_INDEX));
 
-    float R = 0.;
-    float C = 0.;
-    rr_graph_builder.set_node_rc_index(node_index, NodeRCIndex(find_create_rr_rc_data(R, C, rr_rc_data)));
+    const NodeRCIndex rc_index = find_create_rr_rc_data(0, 0, rr_rc_data);
+    rr_graph_builder.set_node_rc_index(node_index, rc_index);
 
     // Use a generic way when adding nodes to lookup.
     // However, since the SINK node has the same xhigh/xlow as well as yhigh/ylow, we can probably use a shortcut
diff --git a/vpr/src/route/rr_graph_generation/clock_network_builders.cpp b/vpr/src/route/rr_graph_generation/clock_network_builders.cpp
@@ -337,16 +337,16 @@ int ClockRib::create_chanx_wire(int layer,
                                 t_rr_graph_storage* rr_nodes,
                                 RRGraphBuilder& rr_graph_builder) {
     rr_nodes->emplace_back();
-    auto node_index = rr_nodes->size() - 1;
+    size_t node_index = rr_nodes->size() - 1;
     RRNodeId chanx_node = RRNodeId(node_index);
 
     rr_graph_builder.set_node_type(chanx_node, e_rr_type::CHANX);
     rr_graph_builder.set_node_coordinates(chanx_node, x_start, y, x_end, y);
     rr_graph_builder.set_node_layer(chanx_node, layer, layer);
     rr_graph_builder.set_node_capacity(chanx_node, 1);
     rr_graph_builder.set_node_track_num(chanx_node, ptc_num);
-    rr_graph_builder.set_node_rc_index(chanx_node, NodeRCIndex(find_create_rr_rc_data(
-                                                       x_chan_wire.layer.r_metal, x_chan_wire.layer.c_metal, g_vpr_ctx.mutable_device().rr_rc_data)));
+    const NodeRCIndex rc_index = find_create_rr_rc_data(x_chan_wire.layer.r_metal, x_chan_wire.layer.c_metal, g_vpr_ctx.mutable_device().rr_rc_data);
+    rr_graph_builder.set_node_rc_index(chanx_node, rc_index);
     rr_graph_builder.set_node_direction(chanx_node, direction);
 
     short seg_index = 0;
@@ -686,8 +686,8 @@ int ClockSpine::create_chany_wire(int layer,
     rr_graph_builder.set_node_layer(chany_node, layer, layer);
     rr_graph_builder.set_node_capacity(chany_node, 1);
     rr_graph_builder.set_node_track_num(chany_node, ptc_num);
-    rr_graph_builder.set_node_rc_index(chany_node, NodeRCIndex(find_create_rr_rc_data(
-                                                       y_chan_wire.layer.r_metal, y_chan_wire.layer.c_metal, g_vpr_ctx.mutable_device().rr_rc_data)));
+    const NodeRCIndex rc_index = find_create_rr_rc_data(y_chan_wire.layer.r_metal, y_chan_wire.layer.c_metal, g_vpr_ctx.mutable_device().rr_rc_data);
+    rr_graph_builder.set_node_rc_index(chany_node, rc_index);
     rr_graph_builder.set_node_direction(chany_node, direction);
 
     short seg_index = 0;
diff --git a/vpr/src/route/rr_graph_generation/rr_graph.cpp b/vpr/src/route/rr_graph_generation/rr_graph.cpp
@@ -2049,7 +2049,7 @@ static void build_rr_chan(RRGraphBuilder& rr_graph_builder,
         int length = end - start + 1;
         float R = length * seg_details[track].Rmetal();
         float C = length * seg_details[track].Cmetal();
-        rr_graph_builder.set_node_rc_index(node, NodeRCIndex(find_create_rr_rc_data(R, C, mutable_device_ctx.rr_rc_data)));
+        rr_graph_builder.set_node_rc_index(node, find_create_rr_rc_data(R, C, mutable_device_ctx.rr_rc_data));
 
         rr_graph_builder.set_node_type(node, chan_type);
         rr_graph_builder.set_node_track_num(node, track);
@@ -2099,9 +2099,8 @@ static void add_and_connect_non_3d_sg_links(RRGraphBuilder& rr_graph_builder,
         rr_graph_builder.set_node_cost_index(node_id, RRIndexedDataId(cons_index));
 
         // Step 4: Assign electrical characteristics
-        float R = 0;
-        float C = 0;
-        rr_graph_builder.set_node_rc_index(node_id, NodeRCIndex(find_create_rr_rc_data(R, C, g_vpr_ctx.mutable_device().rr_rc_data)));
+        const NodeRCIndex rc_index = find_create_rr_rc_data(link.R_metal, link.C_metal, g_vpr_ctx.mutable_device().rr_rc_data);
+        rr_graph_builder.set_node_rc_index(node_id, rc_index);
         // Step 5: Set node type, track number, and direction
         rr_graph_builder.set_node_type(node_id, link.chan_type);
         rr_graph_builder.set_node_track_num(node_id, track_num);
diff --git a/vpr/src/route/rr_graph_generation/rr_graph_3d.cpp b/vpr/src/route/rr_graph_generation/rr_graph_3d.cpp
@@ -85,9 +85,8 @@ void build_inter_die_3d_rr_chan(RRGraphBuilder& rr_graph_builder,
         rr_graph_builder.set_node_coordinates(node, x_coord, y_coord, x_coord, y_coord);
         rr_graph_builder.set_node_cost_index(node, RRIndexedDataId(const_index_offset + link.parallel_segment_index));
         rr_graph_builder.set_node_capacity(node, 1); // GLOBAL routing handled elsewhere
-        float R = 0;
-        float C = 0;
-        rr_graph_builder.set_node_rc_index(node, NodeRCIndex(find_create_rr_rc_data(R, C, mutable_device_ctx.rr_rc_data)));
+        const NodeRCIndex rc_index = find_create_rr_rc_data(link.R_metal, link.C_metal, mutable_device_ctx.rr_rc_data);
+        rr_graph_builder.set_node_rc_index(node, rc_index);
 
         rr_graph_builder.set_node_type(node, e_rr_type::CHANZ);
         rr_graph_builder.set_node_track_num(node, track_num);
diff --git a/vpr/src/route/rr_graph_generation/rr_graph_tile_nodes.cpp b/vpr/src/route/rr_graph_generation/rr_graph_tile_nodes.cpp
@@ -34,9 +34,8 @@ void add_classes_rr_graph(RRGraphBuilder& rr_graph_builder,
         rr_graph_builder.set_node_coordinates(class_inode, (short)root_loc.x, (short)root_loc.y, (short)(root_loc.x + physical_type->width - 1), (short)(root_loc.y + physical_type->height - 1));
         VTR_ASSERT(root_loc.layer_num <= std::numeric_limits<short>::max());
         rr_graph_builder.set_node_layer(class_inode, root_loc.layer_num, root_loc.layer_num);
-        float R = 0.;
-        float C = 0.;
-        rr_graph_builder.set_node_rc_index(class_inode, NodeRCIndex(find_create_rr_rc_data(R, C, mutable_device_ctx.rr_rc_data)));
+        const NodeRCIndex rc_index = find_create_rr_rc_data(0, 0, mutable_device_ctx.rr_rc_data);
+        rr_graph_builder.set_node_rc_index(class_inode, rc_index);
         rr_graph_builder.set_node_class_num(class_inode, class_num);
     }
 }
@@ -78,7 +77,7 @@ void add_pins_rr_graph(RRGraphBuilder& rr_graph_builder,
                 rr_graph_builder.set_node_capacity(node_id, 1);
                 float R = 0.;
                 float C = 0.;
-                rr_graph_builder.set_node_rc_index(node_id, NodeRCIndex(find_create_rr_rc_data(R, C, mutable_device_ctx.rr_rc_data)));
+                rr_graph_builder.set_node_rc_index(node_id, find_create_rr_rc_data(R, C, mutable_device_ctx.rr_rc_data));
                 rr_graph_builder.set_node_pin_num(node_id, pin_num);
                 // Note that we store the grid tile location and side where the pin is located,
                 // which greatly simplifies the drawing code
diff --git a/vpr/src/route/rr_graph_generation/rr_graph_timing_params.cpp b/vpr/src/route/rr_graph_generation/rr_graph_timing_params.cpp
@@ -174,7 +174,7 @@ void add_rr_graph_C_from_switches(float C_ipin_cblock) {
     Couts_to_add = new float[rr_graph.num_nodes()];
     for (size_t i = 0; i < rr_graph.num_nodes(); i++)
         Couts_to_add[i] = 0;
-    for (const RRNodeId& inode : rr_graph.nodes()) {
+    for (const RRNodeId inode : rr_graph.nodes()) {
         for (t_edge_size iedge = 0; iedge < rr_graph.num_edges(inode); iedge++) {
             switch_index = rr_graph.edge_switch(inode, iedge);
             to_node = size_t(rr_graph.edge_sink_node(inode, iedge));
@@ -187,13 +187,13 @@ void add_rr_graph_C_from_switches(float C_ipin_cblock) {
             }
         }
     }
-    for (const RRNodeId& rr_id : device_ctx.rr_graph.nodes()) {
+    for (const RRNodeId rr_id : device_ctx.rr_graph.nodes()) {
         rr_node_C[(size_t)rr_id] += Couts_to_add[(size_t)rr_id];
     }
 
-    //Create the final flywieghted t_rr_rc_data
-    for (const RRNodeId& rr_id : device_ctx.rr_graph.nodes()) {
-        mutable_device_ctx.rr_graph_builder.set_node_rc_index(rr_id, NodeRCIndex(find_create_rr_rc_data(rr_graph.node_R(rr_id), rr_node_C[(size_t)rr_id], mutable_device_ctx.rr_rc_data)));
+    // Create the final flywieghted t_rr_rc_data
+    for (const RRNodeId rr_id : device_ctx.rr_graph.nodes()) {
+        mutable_device_ctx.rr_graph_builder.set_node_rc_index(rr_id, find_create_rr_rc_data(rr_graph.node_R(rr_id), rr_node_C[(size_t)rr_id], mutable_device_ctx.rr_rc_data));
     }
 
     delete[] Couts_to_add;
diff --git a/vpr/src/route/rr_graph_generation/tileable_rr_graph/tileable_rr_graph_node_builder.cpp b/vpr/src/route/rr_graph_generation/tileable_rr_graph/tileable_rr_graph_node_builder.cpp
@@ -487,7 +487,7 @@ static void load_one_grid_opin_nodes_basic_info(RRGraphBuilder& rr_graph_builder
                     rr_node_driver_switches[node] = delayless_switch;
 
                     // RC data
-                    rr_graph_builder.set_node_rc_index(node, NodeRCIndex(find_create_rr_rc_data(0., 0., rr_rc_data)));
+                    rr_graph_builder.set_node_rc_index(node, find_create_rr_rc_data(0., 0., rr_rc_data));
 
                 } // End of loading OPIN rr_nodes
             } // End of side enumeration
@@ -540,7 +540,7 @@ static void load_one_grid_ipin_nodes_basic_info(RRGraphBuilder& rr_graph_builder
                     rr_node_driver_switches[node] = wire_to_ipin_switch;
 
                     // RC data
-                    rr_graph_builder.set_node_rc_index(node, NodeRCIndex(find_create_rr_rc_data(0., 0., rr_rc_data)));
+                    rr_graph_builder.set_node_rc_index(node, find_create_rr_rc_data(0., 0., rr_rc_data));
 
                 } // End of loading IPIN rr_nodes
             } // End of side enumeration
@@ -589,7 +589,7 @@ static void load_one_grid_source_nodes_basic_info(RRGraphBuilder& rr_graph_build
         rr_node_driver_switches[node] = delayless_switch;
 
         // RC data
-        rr_graph_builder.set_node_rc_index(node, NodeRCIndex(find_create_rr_rc_data(0., 0., rr_rc_data)));
+        rr_graph_builder.set_node_rc_index(node, find_create_rr_rc_data(0., 0., rr_rc_data));
 
     } // End of class enumeration
 }
@@ -637,7 +637,7 @@ static void load_one_grid_sink_nodes_basic_info(RRGraphBuilder& rr_graph_builder
         rr_node_driver_switches[node] = delayless_switch;
 
         // RC data
-        rr_graph_builder.set_node_rc_index(node, NodeRCIndex(find_create_rr_rc_data(0., 0., rr_rc_data)));
+        rr_graph_builder.set_node_rc_index(node, find_create_rr_rc_data(0., 0., rr_rc_data));
 
     } // End of class enumeration
 }
@@ -672,7 +672,7 @@ static void load_one_grid_mux_nodes_basic_info(RRGraphBuilder& rr_graph_builder,
         rr_node_driver_switches[node] = RRSwitchId(vib->get_switch_idx());
 
         // RC data
-        rr_graph_builder.set_node_rc_index(node, NodeRCIndex(find_create_rr_rc_data(0., 0., rr_rc_data)));
+        rr_graph_builder.set_node_rc_index(node, find_create_rr_rc_data(0., 0., rr_rc_data));
     }
 }
 
@@ -900,7 +900,7 @@ static void load_one_chan_rr_nodes_basic_info(const RRGraphView& rr_graph,
             size_t parallel_seg_id = find_parallel_seg_index(seg_id, seg_index_map, wanted_axis);
             float node_R = rr_graph.node_length(rr_node_id) * segment_infs[parallel_seg_id].Rmetal;
             float node_C = rr_graph.node_length(rr_node_id) * segment_infs[parallel_seg_id].Cmetal;
-            rr_graph_builder.set_node_rc_index(rr_node_id, NodeRCIndex(find_create_rr_rc_data(node_R, node_C, rr_rc_data)));
+            rr_graph_builder.set_node_rc_index(rr_node_id, find_create_rr_rc_data(node_R, node_C, rr_rc_data));
 
             if (chan_details.is_track_start(itrack)) {
                 rr_graph_builder.set_node_bend_start(rr_node_id, chan_details.get_track_bend_start(itrack));

Original file line number	Diff line number	Diff line change
`@@ -10,4 +10,4 @@`
`10`	`10`	`*`
`11`	`11`	`* The returned indicies index into DeviceContext.rr_rc_data.`
`12`	`12`	`*/`
`13`		`-short find_create_rr_rc_data(const float R, const float C, std::vector<t_rr_rc_data>& rr_rc_data);`
	`13`	`+NodeRCIndex find_create_rr_rc_data(const float R, const float C, std::vector<t_rr_rc_data>& rr_rc_data);`
Original file line number	Diff line number	Diff line change
`@@ -806,7 +806,8 @@ class RrGraphSerializer final : public uxsd::RrGraphBase<RrGraphContextTypes> {`
`806`	`806`	`inline int init_node_timing(int& inode, float C, float R) final {`
`807`	`807`	`auto node = (*rr_nodes_)[inode];`
`808`	`808`	`RRNodeId node_id = node.id();`
`809`		`- rr_graph_builder_->set_node_rc_index(node_id, NodeRCIndex(find_create_rr_rc_data(R, C, *rr_rc_data_)));`
	`809`	`+ const NodeRCIndex rc_index = find_create_rr_rc_data(R, C, *rr_rc_data_);`
	`810`	`+ rr_graph_builder_->set_node_rc_index(node_id, rc_index);`
`810`	`811`	`return inode;`
`811`	`812`	`}`
`812`	`813`	`inline void finish_node_timing(int& /inode/) final {}`
`@@ -934,7 +935,7 @@ class RrGraphSerializer final : public uxsd::RrGraphBase<RrGraphContextTypes> {`
`934`	`935`	`type);`
`935`	`936`	`}`
`936`	`937`
`937`		`- rr_graph_builder_->set_node_rc_index(node_id, NodeRCIndex(find_create_rr_rc_data(0, 0, *rr_rc_data_)));`
	`938`	`+ rr_graph_builder_->set_node_rc_index(node_id, find_create_rr_rc_data(0, 0, *rr_rc_data_));`
`938`	`939`
`939`	`940`	`return id;`
`940`	`941`	`}`